BRPI0417292B1 - device for mounting a pneumatic servomechanism, method of sharing servomechanism - Google Patents

Abstract

The device has a fixed cylindrical support (101) in which a cover (203) of a pneumatic actuator is housed. A cylindrical cap (104) covers a cylinder (206) that is placed on the cover. A set of rollers (109A, 109B) is driven around the actuator, by a gear (110). The rollers fold an end of a sheet metal forming wall for the cylinder around an end of a sheet metal forming wall for the cover. The internal volume (102) of the support is greater than the volume of the cover. The internal volume (107) of the cap is greater than volume of the cylinder. An independent claim is also included for a fastening method of a pneumatic actuator.

Description

"DEVICE FOR ASSEMBLING A PNEUMATIC SERVOMECHANISM, A METHOD FOR RECALLING SERVOMECANISM".

[01] The present invention patent relates to a device for mounting a pneumatic motor vehicle braking servo. More specifically, the invention relates to a device which makes it possible to securely engage a lid and a cylinder of a pneumatic servo mechanism. The invention also relates to a method which makes it possible to assemble the cylinder and cap using the device of the invention. Finally, the invention relates to a pneumatic servomechanism.

[02] One of the objects of the invention is to provide a servo mechanism that can be safely used in a braking device. Another object of the invention is to prevent dismantling of the servomechanism during use regardless of the thickness of the sheet metal forming the servomechanism. A further object of the invention is to provide a lightweight servomechanism without affecting its strength.

[03] It is possible to mount a servo mechanism between the brake control and the master cylinder of the motor vehicle braking device. The pneumatic servo mechanism has the role of increasing the force exerted on the brake control, so that the hydraulic pressure in the master cylinder is higher.

[04] It is possible to construct a servomechanism with a carcass of approximately cylindrical shape. The housing is formed by a cylinder and a lid. The cylinder and cap are fixedly coupled together. There is a front chamber and a rear chamber arranged on the internal volume of the housing. The front chamber faces the master cylinder and has a variable volume. The rear chamber, equally variable in volume, is geared towards brake control. The front chamber is separated from the rear chamber by a movable partition. The movable partition is formed by a sealed and flexible membrane and a rigid skirt. The front chamber is pneumatically connected to a vacuum source. The rear chamber is pneumatically connected, in a valve controlled manner, to a propelling fluid source. The brake control drives a servo control rod. The stem drive controls valve opening and fluid entry into the rear chamber. The resulting pressure change causes the rigid skirt to move.

[05] During braking, the displacement forces exerted at the servomechanism site are extremely significant. Specifically, the servo chambers are subjected to sudden pressure changes. Especially during braking, air is allowed into the rear chamber. This incoming air pushes the movable partition toward the front chamber. Since the servo carcass housing is made up of two originally independent parts, it is critical that these two parts be firmly joined together. Therefore, it is necessary that the contact between the cover and the cylinder is sufficient so that during braking and more specifically during the propulsion of the skirt, the cylinder is not torn from the cover.

[06] In order to ensure that the cap is correctly coupled to the cylinder, spot welding is actually performed on the outer periphery of the cover and cylinder walls. "Spot welding" means compression welding at localized points. These weld points are evenly distributed throughout the outer periphery of the shell to secure the cylinder to the cap. So far, such assemblies have been sufficient.

[7] However, for some time now, the burden of servomechanism was sought to be reduced. Specifically, the servomechanism and more specifically its housing is formed by sheet metal walls. The thickness of the sheet metal and the shape of the servo mechanism therefore have an influence on its weight. In particular, the aim was to reduce the weight of the servomechanism by reducing the thickness of the sheet metal forming the carcass. The plate thickness and servomechanism shape were modified to obtain the minimum weight. "Minimum weight" means the lowest weight of the servomechanism, which achieves the same stiffness and pullout resistance as a conventional servomechanism.

[08] However, the breaking strength at the junction between the cap and the cylinder is reduced. Consequently, spot welding between cap and cylinder is not fully satisfactory when the thickness of the sheet metal is greatly reduced.

[09] The invention specifically seeks to solve this problem by providing a servomechanism whose shape and thickness of the plate can be modified to obtain the minimum weight. The servomechanism obtained is such that it offers great pullout resistance, including at the junction between the cover and the casing cylinder.

To this end, the invention proposes a device for mounting a servo mechanism and more specifically the cover and cylinder of the servo housing. The mounting device of the invention allows for continuous welding along the entire outer periphery of the housing, cylinder and cap. Continuous welding makes it possible to achieve a strong joining of the two parts together. The contact zone offers greater resistance to pullout forces.

To achieve such continuous welding, the device of the invention is equipped with at least one set of rollers. The rollers revolve around the servomechanism. The rollers come into contact with the servo mechanism at the junction between the cover and the casing cylinder. As they roll, the rollers bend the edge of the sheet metal forming the cylinder wall, around the edge of the sheet metal forming the cover wall.

In a certain embodiment of the invention, the device is equipped with two different roller assemblies. The first set of rollers make it possible to bend the edge of the sheet metal forming the cylinder wall around the edge of the sheet metal forming the lid wall at a first angle. The second set of rollers, in turn, makes it possible to bend the metal plate of the cylinder at a more acute second angle than the first. The rollers of the second set are not pressed against the outer wall of the housing until the rollers of the second set have passed first. [013] Thus, the rollers of the first set of rollers begin to bend the metal plate of the cylinder. The first bending action makes it possible to bend the sheet metal at thirty or sixty degrees from an initial position parallel to the axis of rotation of the device. The metal plate is thus partially pushed inwards towards the center of the servo mechanism. The initial position of the lid wall edge is perpendicular to the cylinder wall edge. "Starting position" means the position in which the cap and cylinder are positioned relative to each other but not joined together. After passing at least one roller from the first set of rollers, the metal plate of the cylinder is turned back towards the metal plate of the cover, which is slightly deformed. One of the rollers of the second set of rollers is then pressed against the housing sheet metal, where the first roller has passed, to further bend the cylinder sheet metal against the cover sheet metal. Ideally, the metal plate of the cylinder is bent ninety degrees after the rollers of the second set of rollers have passed.

[014] The roller assemblies of the device of the invention are, for example, equipped with three rollers each. The rollers of the first set alternate with the rollers of the second set. In the case of a generally circular mounting device, the rollers are evenly distributed over the entire perimeter of the device. Thus, for example, one roller in the first set is 120 ° apart from other rollers in the first set. A roller in the first set is separated 60 ° from the rollers in the second set.

[015] For re-trimming to be performed in two successive steps, the rollers of the second set must be pressed against the housing wall only where the rollers of the first set have already passed. For this purpose, in addition to the rotary movement of the rollers around the servo mechanism, each of the rollers is required to perform an alternating radial movement relative to the servo mechanism. This alternating movement is made possible by an eccentric mechanism of the mounting device. The rollers of the two sets are angularly offset from each other. Nevertheless, the rollers of the same assembly are angularly in phase. In this way, the rollers of the first set and then the rollers of the second set are alternately pushed toward the center of the servomechanism. This is how continuous welding of the servo housing is achieved in one or more complete revolutions of the rollers around the servo.

[016] The invention also proposes a method of mounting the servo housing. The method of the invention makes it possible to continuously calender the lid and the casing cylinder along the entire outer perimeter of the casing.

[017] The subject of the invention is therefore a pneumatic servomechanism intended for the motor vehicle braking device, characterized in that the cap and a cylinder of said servomechanism are coupled together along the entire outer contour.

A further subject of the invention is a device for mounting a pneumatic servomechanism, characterized in that it comprises a fixed cylindrical support whose internal volume is greater than the volume of the servomechanism lid, the lid being housed in the holder, a lid cylindrical roller whose internal volume is greater than the volume of the servo cylinder, said cap imposing an axial load on the cylinder, at least one set of rollers rotated by a motor, with the rollers rotating at least partially around the support.

[019] A further subject of the invention is a method of sharing a servo mechanism, characterized in that it comprises the following steps a servo cover is inserted into a holder of the knurling device, with the upper edge of the cover wall resting on the top edge of an inner wall of the bracket, a servo cylinder is placed over the lid, with the bottom edge of the cylinder wall resting on the top edge of the lid wall, a lid of the knurling device is placed on the bracket, with the edge lower cover by compressing the lower edge of the cylinder wall against the upper edge of the cover wall, a motor is driven, the knurling rollers are required to rotate around the servo mechanism by means of the motor, the lower edge of the cylinder wall cylinder is continuously knurled against the upper edge of the lid wall.

[020] The invention will be better understood by reading the following description and examining the accompanying figures. The latter are given by way of example and in no way limit the invention. The figures represent: Figure 1 illustrates a longitudinal section through a servomechanism housed in the mounting device of the invention;

Figures 2a and 2b illustrate an enlargement of figure 1 at the location of the connection between a cover and a servo-cylinder and a roller of the invention; and [023] Figure 3 shows a cross section of a mounting device of the invention.

Figure 1 illustrates an exemplary embodiment of a device 100 for mounting a servo 200. The device 100 is provided with a fixed bracket 101. In the example shown in figure 1, the bracket 101 is approximately cylindrical in shape. . The internal volume 102 of the holder 101 is such that a rear part 201 of servo 200 can be inserted there. "Rear part 201 of servo 200" means control rod 202 and cap 203 of servo 200. Cap 203 also has the approximately cylindrical shape.

[025] One end 204 of the wall 205 forming the lid 233 abuts the upper edge 105 of a centralizer 106. The centralizer 106 is, for example, of approximate ring shape. The diameter of the ring 106 is approximately equal to the inside diameter of the holder 101 at the upper edge location 103 of the holder 101. Thus, the centralizer 106 is placed at the inner perimeter of the holder 101 at the location of the upper edge 103. The centralizer 106 ensures the correct position of cap 203. "Correct position of cap 203 on bracket 101" means the position that allows device 100 to correctly mount servo 200.

In another embodiment, the centralizer 106 consists of at least two distinct parts. Thus, the centralizer 106 does not fully follow the inner contour of the holder 101. It can be uniformly placed at different points of the internal diameter of the holder 101. The various elements forming the centralizer 106 thus make it possible to support the lid 203 at certain points and center it. In another embodiment, it is also possible to use the centralizer 106. The lid 203 then rests directly on the holder 101 at the location of the upper edge 103 of said holder 101.

After the cap 203 has been placed inside 102 of the holder 101, the cylinder 206 of the servo 200 is positioned. The cylinder 206 forms the front of the servo 200. The cylinder 206 is approximately cylindrical in shape. Cylinder 206 is placed in cap 203 so that edge 208 of wall 209 forming cylinder 206 abuts rim 204 of cap 203. In the example illustrated in Figure 1, edge 211 of a sealing membrane 210 of servomechanism 200 forms a bend 211. Bend 211 is secured between edges 204 and 208 respectively of cap 203 and cylinder 206. Bend 211 specifically provides sealing at the contact location between cap 203 and cylinder 206.

The lid 104 of the mounting device 100 is then placed on the holder 101. The lid 104 is approximately cylindrical in shape. The internal volume 107 of cap 104 is such that cylinder 206 may be fitted therein. First edge 108 of cap 104 rests against edge 208 of wall 206 of cylinder 206. "First edge" means, in the description, the left-hand edge in the figure. Conversely, "second edge" means, in the description, the right-hand edge in the figure. Edge 108 of cap 104 is then pressed in direction D against rim 208 of cylinder 102. This exerts an axial load at the location of the connection between cap 203 and cylinder 206. Fold 211 is compressed between two walls 205 and 209, at the points where they end, respectively 204 and 208.

The rollers 109 (two rollers visible in figure 1) are placed on the outer periphery of the holder 101. Figure 3 illustrates more specifically the arrangement of the rollers 109 of the device 100. The rollers 109 are six in total. Rollers 109A of the first set are interspersed with rollers 109B of the second set. The rollers 109 are evenly placed over the entire periphery of the holder 101.

[030] Figure 1 shows that the rollers are in contact with servo 200 at the location of the connection between cover 203 and cylinder 206.

Figures 2a and 2b illustrate two enlargements, respectively one enlargement of Figure 1, at the contact location between roller 109A and servo 200 and the contact location between roller 109B and servo 200. In both cases, It should be noted that the edge 204 of the cap 203 abuts the upper edge 105 of the centralizer 106. Similarly, the fold 211 of the sealing membrane 210 compressed between the edge 204 of the cap 203 and the edge 208 of the cylinder can be seen. 206 Edge 208 of cylinder 206 is compressed by edge 108 of cap 104. Edge 208 of cylinder 206 is approximately parallel to the axis of rotation of the centralizer 106. Edge 204 of cap 203, in turn, is perpendicular to edge 208. Edge 208 extends to the right in Figure 2a, extending beyond the point of contact with Edge 204.

[032] In the invention, edge 208 can be folded around edge 204 and fold 211 so that edge 208 is ideally perpendicular to the centering shaft 106. The aim is to achieve this curvature throughout the periphery of servo 200 .

For this purpose and as illustrated in Figure 1, the mounting device 100 is equipped with a gear element 110 which rotates the rollers 109 around the servo mechanism 200. The gears of the element are themselves rotated by a motor (not illustrated). The gear element 110 is equipped with two gears 111 and 112. Gears 111 and 112 have different tooth numbers.

By means of the first gear 111, the gear element 110 rotates the entire roller assembly 10 9A and 10 9B around the servo mechanism 200. The second gear 112 rotates a cam 118, imposing a periodic sinuous movement on the rollers 109. Thus and by means of this cam 118, the rollers 109 are not continuously pressed against the walls 205 and 209 of the servo mechanism 200.

When the mounting device 100 is set in motion, the rollers 109 continuously rotate all around the servo 200 and are pressed radially against the walls 205 and 209 of the servo 200 periodically and intermittently. Roller assemblies 109A and 109B are angularly offset. The angular offset arrangement is such that it allows to compress the rollers 109A against the wall of the servo mechanism 200, alternating with the compression of the rollers 109B.

[036] Aiming at obtaining the correct trimming, the goal is to compress rollers 109A radially against servo 200 before rollers 109B. Specifically, the rollers 109A and 109B differ in their actuation angle. Figures 2a and 2b show that rollers 109A and 109B are respectively equipped with bevels 113A and 113B. A bevel cut is made on the upper face of rollers 109A and 109B forming bevels 113A and 113B. The shape of the bevels 113A and 113B is different. Specifically, the actuation angle 114A of the bezel 113A is greater than the actuation angle 114B of the bezel 113B. "Actuation angle" means the angle formed by the chamfer cutting of the bevels 113.

[037] The first contact between roller 109A and edge 208 of wall 206 of cylinder 206 makes it possible to slightly bend edge 208 toward the axis C of holder 101. Roller 109B is then pressed against edge 208, already partially curved. Since the actuation angle 114B is smaller than the actuation angle 114A, it is possible to bend end 208 a little further in the direction of the C axis.

[038] For example, the actuation angle 114A is between 115 ° and 135 °. The actuation angle 114B, in turn, is between 80 ° and 90 °. In the preferred example, the actuation angle 114A is 120 °. In this way, the edge 208 is bent 60 ° during the passage of roller 109A. Then, while passing roller 109B, edge 208 is bent another 25 °. And finally, edge 208 is virtually perpendicular to the centering axis 106. Edge 208 is knurled over edge 104, while simultaneously trapping fold 211.

In the invention, this trimming operation is performed throughout the periphery of the servo mechanism 200. The device 100 performs as many rotations as necessary around the servo mechanism so that the cylinder 206 is secured to the lid 203.

Figure 1 illustrates an exemplary embodiment of the device which enables the rollers 109 to be rotated and forces them to perform radially oscillating movements relative to the axis C of the holder 101.

The gear 111 of the gear element 110 rotates the pinion 115. There is a component 116 coupled to the pinion 115. The component 116 is therefore rotated by the rotation of the gear 111. The component 116 is thus rotated all the way around the bracket. 101. Gear 112 of gear element 110 rotates pinion 117. Pinion 117 rotates freely relative to component 116. Thus, pinion 117 rotates independently of component 116. Rotation of component 116 and pinion 117 depends respectively on the rotation of gear 111 and gear 112 of gear element 110. The number of gear teeth 111 is different from the number of gear teeth 112. Component 116 and pinion 117 do not rotate, therefore, at the same speed. Pinion 117 rotates cam 118 by means of pinion 119. Cam 118 at least partially follows the inner periphery of component 116.

[042] Rollers 109 are mounted at the upper edge of cam 118. Cam 118 is attached to component 116. Rollers 109 are therefore rotated all around servo 200. But since cam 118 is also in contact with pinion 117, pinion 117 imposes on the cam a oscillating radial movement with respect to the axis C of the holder 101 and the rollers 109.

This additionally causes the oscillating radial movement of each of the rollers 109 around the servo mechanism 200, relative to the C axis of the holder 101. The rollers 109 are therefore periodically compressed against the wall of the servo mechanism 200, moving apart in then. The angularly offset arrangement of rollers 109A and rollers 109B makes it possible to first compress rollers 109A against the wall of servo 200. Rollers 109B are compressed only after rollers 109B have passed.

Claims (12)

1. "DEVICE FOR MOUNTING A PNEUMATIC SERVOMECANISM", comprising a fixed cylindrical support (101) whose internal volume (102) is greater than the volume of the servo mechanism cover (203), the cover being housed in the support, a cylindrical cover (104) whose internal volume (107) is greater than the volume of the servomechanical cylinder (206), imposing to said cap an axial load on the cylinder, characterized by having at least one set of rollers (109A, 109B) rotated by a motor, with the rollers rotating at least partially around the bracket. 2. "DEVICE FOR ASSEMBLING A PNEUMATIC SERVICE" as claimed in 1, characterized in that it is equipped with a first roller assembly (109A) and a second roller assembly (109B) by rotating the two roller assemblies. at least partially around the stand. 3. "DEVICE FOR MOUNTING A PNEUMATIC SERVICE", as claimed in 1 or 2, characterized in that it is equipped with a centralizer (106) resting on the upper edge (103) of the fixed bracket, a lid resting on the ring centering device having an inner diameter approximately equal to the diameter of the servo cover. 4. "DEVICE FOR ASSEMBLING A PNEUMATIC SERVOMECANISM", as claimed in 2 or 3, characterized in that the first and second set of rollers are alternated. 5. "DEVICE FOR ASSEMBLING A PNEUMATIC SERVICE", as claimed in 2 or 3, or 4, characterized in that the first set of rollers is equipped with three rollers and the second set of rollers is also equipped with three rollers, the first rollers being 120 ° apart and 60 ° from the second rollers. 6. "DEVICE FOR ASSEMBLING A PNEUMATIC SERVICE", as claimed in 2 or 3, or 4, or 5, characterized in that the first rollers are equipped with a bevel (113A), said bevel having an actuation angle. (114A) between 115 and 135 °, and the second rollers are equipped with a bevel (113B), said bevel having an actuation angle (114B) between 80 and 90 °. 7. "DEVICE FOR ASSEMBLING A PNEUMATIC SERVOMECANISM", as claimed in 6, characterized in that the actuation angle of the first roller bevels is 120 ° and the actuation angle of the second roller bevels is 85 °. 8. "DEVICE FOR ASSEMBLING A PNEUMATIC SERVICE", as claimed in 2 or 3, or 4, 5, or 6, or 7, characterized in that it is equipped with a gear element (110) which places the rotating rollers and because the gear element is equipped with two gears, the number of teeth of the first gear (111) being the gear element that rotates the two sets of rollers around the servo mechanism, unlike the number of teeth of the second gear (112) of said gear member, and the fact that the second gear imposes an oscillating radial movement of the rollers relative to the shaft (C) of the support by means of a cam (118). 9. "SERVICE RECYCLING METHOD", which comprises the following steps: the servo mechanism cover (203) (200) is inserted into the holder (101) of a trimming device (100), with the upper edge (204) of the wall (205) the lid resting on the upper edge (103) of the inner wall of the holder; the servo cylinder (206) is placed in the lid, with the lower edge (208) of the cylinder wall (209) abutting the upper edge of the lid wall; the lid (104) of the knurling device is placed in the holder with the lower edge (108) of the lid compressing the lower edge of the cylinder wall against the upper edge of the lid wall; characterized by predicting the steps in which a motor is driven; the knurling rollers (109) are required to rotate around the servo mechanism by means of the motor; and the bottom edge of the cylinder wall is continually knurled against the top edge of the lid wall. 10. "SERVICE RECYCLE METHOD", as claimed in 9, characterized in that it comprises the following step the rollers are required to perform a radially oscillating movement with respect to the axis (C) of the support. 11. "SERVICE RECYCLE METHOD", as claimed in 10, characterized in that it comprises the following step the rollers are required to perform a radially oscillating movement in relation to the support axis (C) by means of an eccentric (118). ) driven by a gear element (110). 12. "METHOD OF RECHARDING SERVICE", as claimed in 9, or 10, or 11, characterized in that the following step comprises the lower edge of the cylinder wall being knurled against the upper edge of the lid wall by successive application. Rollers (109A) equipped with a first actuation angle (114A) and Rollers (109B) equipped with a second actuation angle (114B), the first actuation angle being greater than the second actuation angle.